Many electronic circuits function, at least in part, to provide power to a load to thereby effectuate some intended purpose. In general, such driver circuits include a power transistor that can be operated to make or break a current path that includes the load and the power source.
In many such applications, a short circuit across the load can occur. When this happens, the power transistor used in the driver circuit may become damaged due to excessive current flow. Therefore, various prior art approaches have been proposed to attempt to avoid or minimize the risk of such damage.
Depending upon the application, such prior art approaches may be undesirable or unacceptable due to functioning characteristics, complexity, cost, or response capabilities. Further, many such prior art approaches require the use of a current sense resistor in series with the power transistor. In some application settings, such a resistor should be avoided.
There therefore exists a need for short circuit protection in a power driver that will respond quickly to fault conditions and protect the switch in a relatively simple and cost effective manner, while simultaneously avoiding use of a current sense resistor in series with the power transistor.